Verification of tracks made of Rose

October 21, 2021

I made five tracks of Tropical Storm Rose, before it was assessed as a tropical cyclone. I made one more track after cyclogenesis. Additionally, within 504 hours of cyclogenesis, there were three instances, when I missed cyclogenesis entirely.

As of this analysis, best track positions are available September 16, 18Z thru September 24, 06Z, and as such, position comparisons are possible only for this timespan.

Since I give only SSHS categories in my tracks, I don't calculate intensity errors in units of speed, but in categories. For this purpose, I define tropical or subtropical storms as "Category 0", tropical or subtropical depressions as "Category -1" and non-existence of a tropical or subtropical cyclone as "Category -2".

In the five tracks (made before operationally recognized cyclogenesis), formation times ranged between September 18, 00Z and September 22, 06Z. Average was September 19, 05Z and median was September 18, 12Z.

In the eight cases (5 tracks, before the tracks and data agreed, that tropical storm would remain the peak intensity, and 3 complete misses), peak intensity ranged between Category -2 and Category 3. Average was Category -0.5 and median was Category -1.

In the six tracks (made before operationally recognized degeneration), dissipation times ranged between September 19, 06Z and September 25, 00Z. Average was September 23, 09Z and median was September 25, 00Z.

At the lead time of 1 day (24 hours), there were 1 hit, 0 false detections and 0 misses. 1 available position comparison produces an average error of 59 nautical miles.

At the lead time of 2 days (48 hours), there were 1 hit, 1 false detection and 1 miss. 2 available position comparisons produce an average error of 128 nautical miles.

At the lead time of 3 days (72 hours), there were 1 hit, 0 false detections and 1 miss. 1 available position comparison produces an average error of 164 nautical miles.

At the lead time of 4 days (96 hours), there were 2 hits, 1 false detection and 1 miss. 3 available position comparisons produce an average error of 148 nautical miles.

At the lead time of 5 days (120 hours), there were 2 hits, 0 false detections and 2 misses. 2 available position comparisons produce an average error of 227 nautical miles.

At the lead time of 6 days (144 hours), there were 3 hits, 0 false detections and 1 miss. 3 available position comparisons produce an average error of 297 nautical miles.

At the lead time of 7 days (168 hours), there were 2 hits, 1 false detection and 1 miss. 3 available position comparisons produce an average error of 406 nautical miles.

At the lead time of 8 days (192 hours), there were 2 hits, 1 false detection and 0 misses. 3 available position comparisons produce an average error of 487 nautical miles.

At the lead time of 9 days (216 hours), there were 1 hit, 1 false detection and 1 miss. 2 available position comparisons produce an average error of 536 nautical miles.

At the lead time of 10 days (240 hours), there were 0 hits, 1 false detection and 1 miss. 1 available position comparison produces an average error of 478 nautical miles.

At the lead time of 11 days (264 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 12 days (288 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 13 days (312 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 14 days (336 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 15 days (360 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 16 days (384 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 17 days (408 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

At the lead time of 18 days (432 hours), there were 0 hits, 0 false detections and 1 miss. No available position comparisons.

At the lead time of 19 days (456 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

At the lead time of 20 days (480 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

At the lead time of 21 days (504 hours), there were 0 hits, 0 false detections and 2 misses. No available position comparisons.

Circle coloration scheme